Hydraulic set packers can be used for a number of implementations downhole. For example, a dual bore packer that is hydraulically set can be used for an electric submersible pump (ESP) system, such as shown in FIG. 1. In the ESP system, surface equipment 18 connects via production tubing 12, control line 14, and electric cable to a dual bore, hydraulically set packer 30. A packing element on the packer 30 seals in the casing 10, and slips on the packer 30 engage the casing wall.
Internally, the packer 30 communicates the production tubing 12 via one bore of the packer 30 to an electric submersible pump 20. The packer 30 also communicates a feed-through of the electrical cable 16 via another bore on the packer 30 to the motor of the pump 20. (Mating connectors and a sealed mandrel can be used for the feedthrough to maintain a pressure barrier.) The packer 30 is typically set hydraulically using hydraulics communicated via the control line 14. Ultimately, the packer 30 serves a number of purposes, such as preventing free gas from venting up the annulus, isolate the annulus above the pump 20, etc.
FIGS. 2A-2B illustrate two types of hydraulic set packers 30A-B of the prior art as may typically be used for an ESP system. The hydraulic set packers 30A-B can be set in two different directions, including up and down component movement as in FIG. 2A or all components can move in upward direction as in FIG. 2B. In particular, the packer 30A in FIG. 2A includes a hydraulic setting component 34 disposed between slips 38 (at the packer's downhole end 32d) and a packing element 36 (at the packer's uphole end 32u). Activation of the hydraulic setting component 34 uses down component movement to the set the slips 38 and uses up component movement to set the packing element 36.
In contrast to this arrangement, the packer 30B in FIG. 2B includes the hydraulic setting component 34 disposed toward the downhole end 32d of the packer 30B, followed by the slips 38 and the packing element 36 towards the uphole end 32u. Activation of the hydraulic setting component 34 uses up component movement to the set both the slips 38 and the packing element 36.
Issues can occur when setting these hydraulic set packers 30A-B. In one example, the packer 30A-B may be used in a well suffering high loss rates. In setting the packer 30A-B, fluid in the annulus of the casing around the packer 30A-B may flow rapidly further down the casing and into the lossy formation. In another example, a valve may be opened below the packer 30A-B prior to setting the packer 30A-B. The opening of the valve may cause a high flow rate (˜12 bbl/min at ˜150 deg-F) to pass across the outside of the packer 30A-B while the packer 30A-B is setting. Setting the packers 30A-B in such high flow rates in either of these situations can cause failure of the packer 30A-B.
What is needed is a packer that can be set in high flow rates without causing damage during setting. The subject matter of the present disclosure is directed to overcoming, or at least reducing the effects of, one or more of the problems set forth above.